The collarbone (clavicle) and the breastbone (sternum) are connected to each other by a cartilaginous joint which, when damaged, causes discomfort. One might consider replacing the joint by a prosthesis, but known types of prostheses are not suitable for this purpose, since their implantation generally requires distraction of the bones which are to be connected by the prosthesis. However, the collarbone and the breastbone can be distracted only with difficulty.